1. Field of the Invention
The invention relates to stable, aqueous concentrates of perglutaric acid useful in the preparation of aqueous bleach, detergent and antimicrobial compositions.
2. Description of the Prior Art
It is known that percarboxylic acids are excellent oxidizing and disinfecting agents. It also is known that lower aliphatic percarboxylic acids, such as peracetic acid and perpropionic acid, can form stable solutions with a high peracid content. These peracids, however, have a very pungent odor, which makes their handling difficult and even hazardous. A further considerable disadvantage of peracetic acid is its relatively high volatility, which in addition to resulting in an annoying odor, leads to an undesirable uptake in man, animals and plants through inhalation and resorption and could preclude its use on toxicological grounds.
It would be highly desirable therefore if stable, aqueous percarboxylic acid solutions containing relatively high concentrations of percarboxylic acid could be prepared which could be diluted with water for ultimate use and which would be odorless or have only a slight odor.
Percarboxylic acids, which have little odor and which are water soluble exist in the class of lower dicarboxylic acids. Thus, maleic acid and succinic acid form practically odorless, water soluble peracids. However, stable solutions of high peracid content cannot be prepared from these peracids. Thus, when persuccinic acid is prepared from succinic anhydride and hydrogen peroxide, the initial high content of persuccinic acid decreases upon extended storage. Furthermore, the decomposition of persuccinic acid leads to crystallization of the resulting succinic acid. The solubility of peradipic acid in water is too low to permit the preparation of solutions of adequate peracid content. Aqueous solutions of perdiglycolic acid can be prepared but the peracid content of such solutions is too low. There is therefore a need for a solution of a technical problem of long standing, namely, the preparation of stable, nearly odorless, aqueous peracid concentrates which markedly improve and simplify the handling of organic per-compounds not only as disinfectants but also in oxidation and bleaching processes. Concentrated solutions in the field of peracids are desirable since dilute peracid solutions are not stable, and hence, cannot be marketed.